For the second time this month, ethical questions rocked the U.S. Senate race in New Jersey, as Democrats rolled out the Gatling guns to take aim at critics of Sen. Robert Menendez and Republicans fanned talk of the senator dropping out of the race.

The frenetic state of the campaign came after yesterday's disclosure that Menendez's longtime friend and fund-raiser Donald Scarinci was secretly taped asking a psychiatrist with government contracts in Hudson County to hire a doctor as a "favor" to Menendez.

Scarinci declined to comment on the tape, which was obtained by The Inquirer. Menendez denied any knowledge of it.

Looking to defuse the ethical questions that have swirled around his campaign, Menendez starting running an ad accusing the Republican candidate, Thomas H. Kean Jr., of falsely attacking him, while his Democratic supporters sought to discredit Oscar Sandoval, who taped Scarinci, and make it clear that Menendez will not drop out of the race.

Democratic Party chairman Joe Cryan and Gov. Corzine, who picked Menendez in January to fill out his unexpired U.S. Senate term, both said they were standing with Menendez until the end of the race.

If that sounds familiar, it is. Earlier this month when reports that the U.S. attorney subpoenaed records of a nonprofit group that rented office space from Menendez surfaced, the party publicly closed ranks around Menendez.

Corzine spokesman Anthony Coley said: "Bob Menendez is our guy. He was our guy in January when the governor chose him. He's the governor's choice today."

Corzine's chief of staff, Tom Shea, said the governor was at a fund-raiser for Menendez last night and the night before. He said no one in the party had asked him to ditch Menendez.

But as support from national, state and Hudson County Democrats poured in, some party players suggested that they'd already come to grips with Menendez's possible loss and were concentrating on local races such as the county executive race in Bergen County and next year's round of state legislative races.

"Generally, my colleagues are much more interested in local issues and state issues than federal issues," said State Sen. Ray Lesniak (D., Union). "That's their take on things."

Lesniak, who is frequently involved in dramatic Democratic Party decisions, said yesterday there was no significant movement to dump Menendez and substitute a new candidate. He did, however, acknowledge that some in his party were discussing the possibility.

Just in case, and for dramatic effect, Republicans held a teleconference from Washington yesterday to say they'd fight any efforts to find a substitute for Menendez on the ballot.

There is precedent for a late switch.

In 2002, U.S. Sen. Robert Torricelli dropped his reelection bid Sept. 30 after his poll numbers went into free fall because of a campaign-finance scandal. Democrats replaced Torricelli with former U.S. Sen. Frank Lautenberg, even though the deadline for replacing a candidate had passed - an act upheld by the courts.

The Menendez campaign, though, showed no signs of slowing down.

The campaign aired a 60-second radio ad in New York and Philadelphia media markets attacking Kean, saying he was "falsely attacking Bob Menendez. But Tom Kean Jr. is the one under the ethical cloud."

The Menendez campaign denied that it had been teased into playing Kean's game by talking about ethics instead of the war in Iraq - an issue that resonates well for Menendez among voters.

"We can walk and chew gum at the same time," said Menendez campaign press secretary Matthew Miller, adding that the campaign would continue to escalate its TV advertising, which began two weeks ago. Kean is expected to begin TV advertising next week, a week later than the campaign first indicated.

The Menendez campaign also scrambled to discredit Sandoval, the psychiatrist who taped Scarinci, saying he dated and drugged a patient and bribed Hudson County politicians - in one instance giving cash and Viagra to a freeholder for contracts.

After the FBI caught Sandoval paying bribes to Hudson County officials, he became an informant.

The county is suing him to recover money from his government contracts.

Hudson County Executive Tom DeGise issued a statement yesterday saying: "Oscar Sandoval wormed his way into the pockets of our taxpayers through bribery and disgraceful professional practices... . Shame on Tom Kean Jr., for aligning himself with such a person in an attempt to score cheap political points."

Democrats also touted a Zogby/Wall Street Journal poll that showed Menendez was ahead of Kean by 6 percentage points - a sure sign that the party wanted to show Menendez could win even as he is under siege.

Rutgers University's Eagleton Institute of Politics also released a poll that put the two in a virtual tie. Menendez had the support of 45 percent and Kean had 44 percent of 404 likely voters in a poll taken Sept. 24 to 26 with a margin of error of plus or minus 4.9 percentage points.